Lubricant-gun follower packing



United States Patent 3,038,768 LUBRICANT-GUN FOLLOWER PACKING JonathanKludt, St. Louis, Mo., assignor to The McNeil Machine & EngineeringCompany, Akron, Ohio, a corporation of Ohio Filed Sept. 8, 1959, Ser.No. 838,673 4 Claims. (Cl. 277-212) This invention relates to a packingunit for lubricant guns, and more particularly to unitary packing forfollowers of grease guns of the type having a barrel for containing asupply of grease, a pump at one end of the barrel, and a followerslidable in the barrel for forcing grease toward the pump.

In the coassigned Klein et a1. United States Patent 2,886,215 dated May12, 1959, entitled, Lubricant Gun, there is shown a special followermade of rubber or the like for a grease gun of the class above describedwhich, in one position, is adapted for easy entry into a greasecartridge such as may be inserted in the barrel of the gun and forsliding sealing engagement in the cartridge, and which, in aflipped-over position, is adapted to enable the gun to be used as a bulkgrease gun (in which case there is no cartridge in the barrel and thebarrel is loaded by means of a filler pump or suction).

Among the several objects of this invention may be noted the provisionof a special follower packing for a grease gun of the class describedwhich, without any necessity for flipping it over, adapts the gun foruse either as a cartridge-type gun or as a bulk grease gun, the followerbeing adapted for easy entry into a cartridge and to make a tight sealagainst the cartridge to prevent by-passing of grease around thefollower and, without flipping over the packing, to make a tight sealagainst the barrel when the gun is used as a bulk grease gun; and theprovision of follower packing having the stated features which iseconomical to manufacture and reliable in use. Other objects andfeatures will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafterdescribed, the scope of the invention being indicated in the followingclaims.

In the accompanying drawings, in which one of various possibleembodiments of the invention is illustrated,

FIG. 1 is a longitudinal section of a grease gun, illustrating acartridge in the barrel of the gun, and illustrating the follower of thegun in an intermediate position in the cartridge;

FIG. 2 is an enlarged section taken on line 2-2 of FIG. 1, illustratingthe follower near the pump of the s FIG. 3 is a view similar to FIG. 2,without a cartridge in the barrel, showing the follower as it appearswhen the gun is used as a bulk grease gun;

FIG. 4 is a section of the packing mem ber per se as it appears whendisassembled from the gun and uncompressed; and,

FIG. 5 is a section taken on line 5-5 of FIG. 1.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawmgs.

Referring to the drawings, a grease gun is shown to comprise a containeror barrel 1 for containing a supply of grease. The barrel may consist,for example, of a metal tube. At one end of the barrel 1 (this endconstituting the forward end of the barrel) is a pump generallydesignated P. The pump comprises a head 3 screwed on the forward end ofthe barrel and having a bore 5 extending transversely with respect tothe barrel. This bore constitutes the pump cylinder. A pump plunger 7reciprocates in the bore or cylinder 5. The plunger 3,fl38,758 PatentedJune 12, 1962 extends out of one end of the cylinder 5 (the rearward endof the cylinder). A hand lever 9 is pin-connected at 11 adjacent one endto the end of the plunger which extends out of the cylinder. A link 13is pin-connected at 15 to this end of the lever and pin-connected at 17to the head 3. The arrangement is such that by swinging the lever awayfrom the barrel 1, the plunger 7 is pulled out through a priming orreturn stroke, and by swinging the lever toward the barrel, the plungeris pushed in through a pressure stroke.

The head 3 is formed with a lateral inlet port 19 for the cylinder 5through which grease may flow from the barrel 1 into the cylinder 5 whenthe plunger 7 is fully retracted through a full return stroke. In thebarrel is a follower 21 biased toward the head 3 by a spring 23 forforcing grease from the barrel into the cylinder. The forward end of thecylinder 5 is closed by a plug 25. The head is formed with a lateraloutlet port 27 adjacent the forward end of the cylinder. Screwed in theoutlet port 27 is an outlet pipe 29. On the outer end of the pipe is aconventional hydraulic coupler 31. The forward end portion of thecylinder 5 is enlarged as indicated at 33 to provide a forwardly facingvalve seat 35 inward of the outlet port 27. A valve ball 37 is biasedtoward this seat by a spring 39 reacting from the plug 25. The head 3 isprovided with a conventional filler nipple 41 (see FIG. 2) for fillingof the barrel 1 with bulk grease by means of a conventional filler pump.

In accordance with this invention, the follower 21 is of specialconstruction, comprising a hub generally designated 45 carrying aspecial resilient packing member or device 47 which may be made of asuitable flexible greaseresistant synthetic rubber or the like. Thepacking member 47 (shown normally in FIG. 4 as manufactured) is formedas a cup having a central cylindrical sleeve 49 at a head end (itsforward end toward the forward end of the barrel 1). The head end isformed as an integral outwardly extending circular flange 511 having aflat bottom (forward) face 53 and a. conical top (rearward) face 55.Flange 51 is thus of annular conical form, its thickness diminishingfrom sleeve 49 out to its periphery. Extending back from the peripheryof the flange 51 is a barrel-shaped annular wall portion 57. Thissurrounds the sleeve 49, being spaced radially outward from the sleeve.

In its unstressed, normal or unconfined condition, annular wall portion57 of packing member 47 is of rounded bulbous or barrel form, convex asregarded from the outside, concave as regarded from the inside (see FIG.4). It extends back beyond the rearward end of the sleeve 49, where ithas a thickened internal annular head or shoulder 59 formed with aninternal cylindrical surface 61 coaxial with the sleeve 49. Extendingrearward from the outer margin of the bead '57 is an annular conical lip63 which flares outward from the bead, the outer edge of the lip at itsrearward end (which is its larger end) having approximately the samediameter as the maximum diameter of the bulbous annular wall portion 57when the packing member is in its unstressed, normal or unconfinedcondition. Lip 63 is thin relative to the bead 59. The packing member 47is formed with an annular grooove 64 surrounding the flange 51 on therearward side of the flange at the juncture of the flange with thebulbous annular Wall portion 57, so that the annular wall portion 57 isrelatively thin at its juncture with the flange 51. From this region,the annular wall portion gradually increases in thickness back to thehead 59.

The hub 45 comprises a tubular metal bushing 65 provided with forwardand rearward end heads 57 and 69. The forward end head 67 is constitutedby a flat circular metal washer surrounding the bushing and engaging anenlarged forward end portion 71 of the bushing. The

sleeve 49 of packing member 21 has a tight sealing fit on the bushing65, the flat forward face 53 of flange 51 of packing member 21 engagingthe forward end head 67. The rearward end head 69 is constituted by acup-shaped sheet metal member having a central opening receiving areduced-diameter portion of bushing 65 at the rearward end of thelatter, and is held in place on the bushing by peening as indicated at73. Rearward end head 69 engages the rearward end of the sleeve 49 ofpacking member 21. It has a rearwardly directed cylindrical wall 75coaxial with the bushing 65 and the sleeve 49 of packing member 21. Theoutside diameter of wall 75 corresponds to the diameter of the internalcylindrical surface 61 of the bead 57 of packing member 21, the beadthereby having a sliding sealing fit on surface 61. Wall 75 has arearward outwardly directed flange 77 overlying the bead and on theinside of lip 63, flange 77 being spaced from the rearward end of thebead. The bushing 65 has an axial bore 79 with a counterbore 81 at itsrearward end receiving packing 83. This packing is compressed in thecounterbore 81 by a washer 85 held in place by peening a portion of thebushing as indicated at 87.

At 89 is indicated a follower rod which extends through the bushing 65.Bushing packing 83 has a sliding sealing fit on the rod. The barrel 1has a cap 91 threaded on its rearward end (see FIG. 1). The follower rodhas a length somewhat greater than that of the barrel and extendsslidably through a central opening 93 in the cap. The outer end of therod 87 is formed as a handle as indicated at 95. The opening 93 may becircular with a lateral notch as in the gun shown in US. Patent2,394,488, and the rod 89 may have a groove 97 as in said patent forlocking the rod in a retracted pulled-out position by angling the rod tobring the groove into the lateral notch. At the inner end of thefollower rod 89 is a cross-pin 99. Secured to the forward end head 67 ofhub 45 as by spotwelding is a U-shaped sheet metal member 101 having aslot 163 of the elongate centrally enlarged shape shown in FIG. 5. Therod 89 may be turned to align pin 99 with slot 103 or to disalign itfrom this slot.

As previously stated, the annular wall portion 57 of the flexibleresilient packing member 47 is of bulbous form in its unconfineduncompressed condition out of the barrel of the gun. its maximumdiameter is then somewhat greater than the internal diameter of thebarrel 1 of the gun. For example, in the case of a barrel having aninternal diameter of two and one-eighth inches (2.125) the maximumdiameter of annular wall portion would be within the limits of 2.155"and 2.170. The diameter of the outer periphery of the lip 63 at itsrearward (large) end is the same, i.e., 2.155-2.170. The forward endhead 67 on bushing 65 is of smaller diameter than the internal diameterof a cartridge to be loaded in the barrel 1.

FIGS. 1 and 2 show the gun in use as a cartridge gun, i.e., loaded witha cartridge of grease comprising a tube T which is fill-ed with greaseand which, as supplied, has closure caps (not shown) at its ends. Thetube T has a large opening at one end and a small opening at the other.To load a cartridge in the gun, the pump P is removed from the barrel 1.The follower rod 89 is pulled out and locked in pulled-out position byangling it for engagement of groove 97 in the lateral notch of theopening 93 in the barrel cap 91. This pulls the follower 21 back to therearward end of the barrel and holds it there against the bias of spring23. The caps having been removed from the tube T, the tube T is insertedinto the barrel 1 (from the forward or pump end of the barrel) with theend of the tube T having the large opening being inserted first.

The pump P is then replaced on the barrel 1, and the follower rod 89unlocked from the barrel cap 91. Holding the follower rod 89 back sothat the pin 99 is located between plate 101 and the forward end ofbushing 65, the follower rod is turned to disalign pin 99 and slot 103.Then the follower rod 89 is pushed in. This pushes in the follower 21.As the follower is pushed in, the bulbous annular wall portion 57 of thepacking member 47 of the follower is readily radially compressed togenerally cylindrical form as it enters the end of the tube T so that iteasily enters the tube and comes into sliding sealing engagement withthe interior surface of the tube to force the grease in the tube towardthe pump P without leakage of grease past the packing member. As theannular wall portion 57 is compressed on entering the tube T, itsrearward end slides rearward on cylindrical wall 75 of the rearward endhead 69, the latter serving to keep the annular wall portion 57 fromcollapsing thereby to prevent the pressure of the grease from breakingthe seal between the annular wall portion 57 and the tube T. The lip 63is also compressed to generally cylindrical form. Pressure is applied byhand to the follower rod 89 to expel any air that may have been trappedby the ball check valve 37, and then the follower rod is disengaged fromthe follower 21 by aligning the pin 99 and slot 193 and pushing the rodinto the FIG. 1 position. Then the gun is ready for use.

If the gun is to be loaded with bulk grease instead of a cartridge, nochange in the follower 21 is needed. The annular wall portion 57 of thepacking member 47 is then radially compressed substantially tocylindrical form in the barrel (see FIG. 3), not so much as when in acartridge tube T, but still sufficient for sliding sealing engagementwith the internal surface of the barrel. The gun may be loaded with bulkgrease either by utilizing a filler pump to pump grease into the barrel1 via filler nipple 41, or by removing the pump P, inserting the openend of the barrel in a container of grease, and sucking grease into thebarrel by pulling back the follower 21. In the latter case, lip 63 isparticularly effective to insure against such leakage of air around thefollower as would break the suction, being pressed outward into tightengagement with the barrel by the air pressure built up in the barrelrearward of the follower on pulling the follower back.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

I claim:

1. A follower packing unit composed throughout of resilient material andfor use in the supply barrel of a lubricant gun operable with or withoutlubricant cartridges, comprising a cup formed of a flexible annular wallwhich normally is of bulged barrel shape, said cup having an open endformed by an outwardly flaring lip shaped for marginal flexibility andconnected with the annular wall by an inwardly directed supportingshoulder shaped to have less marginal flexibility than that of said wallor said lip, a central sleeve, the other end of the barrel-shaped wallbeing connected with said sleeve by a supporting flange which is shapedalso to have less flexibility than that of said wall or said lip, themarginal portions of said flange forming a connection with the well,said sleeve, flange and shoulder being adapted to form connections forthe packing with central follower parts in the barrel of the gun, saidannular wall being adapted to change from its normal barrel shape to asubstantially cylindrical shape extending between the flange and theshoulder upon insertion into cylinders of different diameters to effectan elongate seal therebetween, said flaring lip adapted to form anadjacent seal with said cylinders.

2. A follower packing unit according to claim 1, where- 5 in oppositefaces of the marginal portions of said flange converge where the flangeconnects with the wall.

3. A follower packing unit according to claim 1, wherein the connectionbetween the flange and the wall is grooved to facilitate said change ofthe annular wall from its barrel shape to its cylindrical shape.

4. A follower packing unit according to claim 2, wherein the connectionbetween the flange and the wall is grooved to facilitate said change ofthe annular wall from its barrel shape to its cylindrical shape.

References @iteri in the file of this patent UNITED STATES PATENTSGosling Feb. 1, 1944 Dick July 22, 1947 Vielmo Jan 15, 1957 Klein et al.May 12, 1959 Peras June 2, 1959

